Turbine nozzle and related casting method for optimal fillet wall thickness control

Abstract

In a method of investment casting a turbine nozzle which includes an outer band, an inner band and an airfoil section extending between the inner and outer bands, an improvement including shaping a temporary wax form, and external shell and internal core components used in casting such that during pouring of molten metal into a space created by removal of the wax form, shell material lies on opposite sides of an outer fillet connecting the outer band to the airfoil section. The resulting gas turbine nozzle includes first and second horizontally oriented ribs extending about interior peripheries of the airfoil section vertically adjacent the outer and inner band fillets.

What is claimed is: 
     
       1. A gas turbine nozzle comprising an outer band and an inner band; an airfoil section extending between the outer band and the inner band with an outer band fillet and an inner band fillet, respectively therebetween; and a first horizontally oriented rib extending about an interior periphery of the airfoil section, below and adjacent said outer band fillet. 
     
     
       2. The gas turbine nozzle of claim 1 and further comprising a second horizontally oriented rib extending about the interior periphery of the airfoil section, above and adjacent said inner band fillet.